
31Introduction to Nanosensors
is transduced into mechanical motion. On the contrary, many devices do
not play the roles of both the sensor and the transducer. A photoresistor
changes resistance as a function of impinging light without any energy
conversion. A piezoresistive pressure sensor shows change in piezoresis-
tor value with pressure. The capacitance of a capacitive pressure sensor is
altered by pressure.
A plausible way to distinguish between sensors and transducers is to use
the term “sensor” for the sensing component itself and “transducer” for the
sensing component together with associated circuitry. Transducer = sen-
sor + ...